Spaces are allowed; punctuation is not allowed except for periods, hyphens, and underscores.

A valid e-mail address. All e-mails from the system will be sent to this address. The e-mail address is not made public and will only be used if you wish to receive a new password or wish to receive certain news or notifications by e-mail.

Your full name, it's just useful to know who is registering and helps with the approval of your account.